Several interconnected vignettes make up “ Chronicles From the Siege ,” Abdallah Alkhatib ’s harrowing, poignant, sometimes darkly hilarious dispatch from the frontlines of a violent blitz. The drama is shot with a documentarian’s eye and unfolds in the ruins of an unnamed city, but its setting is far from nebulous — not least because of the presence of a few Palestinian flags. The stories are drawn from various sources, including tales from Gaza in recent years, as well as Alkhatib’s own